<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Programa 3</title>
</head>
<body>
    <canvas width="600" height="400"></canvas>
    <a href="relog.html">Ver relog</a>
</body>
<script>
    var pantalla = document.querySelector("canvas");
    var pincel = pantalla.getContext("2d");
    pincel.fillStyle = "lightgray";
    pincel.fillRect(0, 0, 600, 400);
    var color = "blue";
    function exibirAlerta(evento, saludo){
        var x = evento.pageX - pantalla.offsetLeft;
        var y = evento.pageY - pantalla.offsetTop
        console.log(evento, saludo);
        alert("Ud. hizo click en x: "+ x + " y: " + y);
    }
    function dibujarCirculo(evento){
        var x = evento.pageX - pantalla.offsetLeft;
        var y = evento.pageY - pantalla.offsetTop
        pincel.fillStyle = color;
        pincel.beginPath();
        pincel.arc(x,y,10,0,2*3.14);
        //pincel.arc(x,y,radio,anguloInicial,anguloFinal);
        pincel.fill();
        console.log(x + " , " + y);
    }
    function alterarColor() {
        //alert("Funcionó");
        if(color=="blue"){ color = "red";}
        else if(color=="red"){ color = "green";}
        else if(color=="green"){ color = "blue";}
        return false;
    }
    pantalla.oncontextmenu = alterarColor;
    //pantalla.onclick = (e)=> exibirAlerta( e, "¡Hola!");
    pantalla.onclick = dibujarCirculo;
</script>
</html>